Syria's chemical weapons program began in the 1970s with weapons and training from Egypt and the Soviet Union, with production of chemical weapons in Syria beginning in the mid-1980s. Syria's chemical weapons program was one of the largest in the Middle East. For some time, Syria was believed to have the world's third-largest stockpile of chemical weapons, after the United States and Russia. Prior to September 2013 Syria had not publicly admitted to possessing chemical weapons, although Western intelligence services believed it to hold one of the world's largest stockpiles.Congressional Research Service, 12 September 2013, Syria's Chemical Weapons: Issues for Congress In September 2013, French intelligence put the Syrian stockpile at 1,000 tonnes, including Yperite, VX and "several hundred tonnes of sarin". At the time, Syria was one of a handful of states which had not ratified the Chemical Weapons Convention. In September 2013, Syria joined the CWC (formally acceding on 14 October), and agreed to the destruction of its weapons, to be supervised by the Organisation for the Prohibition of Chemical Weapons (OPCW), as required by the convention. A joint OPCW-United Nations mission was established to oversee the destruction process. Syria joined OPCW after international condemnation of the August 2013 Ghouta chemical attack, for which Western states held the Syrian government responsible (whilst Syria and Russia held the Syrian rebels of the Syrian civil war responsible) and agreed to the prompt destruction of its chemical weapons.
The destruction of Syria's chemical weapons that the Assad government had declared was completed by August 2014, yet further disclosures, incomplete documentation, and allegations of withholding part of Syria's chemical weapons stockpile since mean that serious concerns regarding chemical weapons and related sites in Syria remain. On 5 April 2017, the government of Syria allegedly unleashed a chemical attack that killed 70 civilians. A suspected chemical attack on Douma on 9 April 2018 that killed at least 49 civilians has been blamed on the Syrian Government.
As of the fall of the Assad regime in December 2024, Syria retained at least some chemical weapons, whose status was thrown into flux with the sudden shift in the Syrian tactical situation. The new government renew full cooperation with OPCW, which re-established its presence in Syria in November 2025. As of May 2026 an OPCW team found more than 70 previously undeclared chemical munitions (rockets and aerial bombs), as well as raw ingredients for the production of sarin. Rockets of the same type as those used in the Ghouta chemical attack were also found.
Overview
Public stance Prior to entry into force on 14 October 2013 of Syria's instrument accession, Syria was one of five states that had not signed and seven that had not ratified the Chemical Weapons Convention, which prohibits the development, production, stockpiling, transfer, and use of chemical weapons. However, in 1968, Syria acceded to the 1925 Geneva Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases. Syria had repeatedly pledged to ratify the CWC if its neighbouring countries, especially Israel, ratify the convention. In the aftermath of the 2003 invasion of Iraq, Syria stated that it had no chemical weapons, but stated it possessed such weapons in 2012.Syria says it will use chemical weapons if attacked Associated Press 23 July 2012 The Syrian president had earlier alluded to a chemical weapon capability in public statements, in 1990 and 1997.
Western non-governmental organisations stated they believed Syria had an active chemical weapons program.Syria Special Weapons Guide at globalsecurity.org , accessed 24 October 2007.Syria Profile at the Nuclear Threat Initiative , accessed 24 October 2007.Syria and WMD Incentives and Capabilities , Syria Magnus Normark, Anders Lindblad, Anders Norqvist, Björn Sandström, Louise Waldenström, Swedish Defense Research Agency report FOI-R—1290—SE, June 2004, ISSN 1650-1942
In September 2013, Syria provided information about its stockpile to the OPCW as part of its disarmament obligations. However, the exact composition of its declared chemical arsenal will not be disclosed to the public, due to OPCW rules.
Motivation A number of reasons have been postulated for Syria's adoption of a chemical weapon strategy in the 1980s:
to act as a deterrent to Israeli use of nuclear weapons against Syria to compensate for the loss of Egypt as a military ally after the signing of the Egypt–Israel peace treaty in 1979 after recognising the limitations of Syrian air power against Israel in the 1982 Lebanon War, Syria adopted an alternative missile strategy, which required a non-high-explosive warhead to compensate for lack of missile accuracy to act as a deterrent to its powerful neighbour Turkey in any possible dispute.
Stockpiling and production According to some US analysts, Syria was provided with some chemical weapons and delivery systems prior to the 1973 Yom Kippur War. According to US intelligence reports, Syria began to develop its chemical weapons capabilities in the later 1970s, with supplies and training from the Soviet Union, and likely with equipment and precursor chemicals from private companies in Western Europe. However Syrian production of chemical weapons is not believed to have begun until the mid-1980s. The Director of the US Defense Intelligence Agency said in 2013 that the Syrian program had never become fully independent, and remained reliant on the importing of precursor chemicals.
In 1988, a U.S. analyst described Syria's chemical weapon capability as more advanced than the Iraqi chemical weapons program; however, Israel stated in 1989 that Syria had only the "potential for chemical warfare, but not more than that". In the meantime, a Syrian chemical weapons scientist, dubbed as "the chemist" who was recruited by the CIA from 1988 until his execution in 2001, reported that there was a lab known as "Institute 3,000" near Damascus to manufacture chemical weapons, as later revealed in Joby Warrick's Red Line book.
In July 2007, a Syrian arms depot exploded, killing at least 15 Syrians, as well as 10 Iranians.The Spies Inside Damascus Foreign Policy Magazine, BY RONEN BERGMAN, 19 September 2013 Jane's Defence Weekly, a U.S. magazine reporting on military and corporate affairs, believed that the explosion happened when Iranian and Syrian military personnel attempted to fit a Scud missile with a mustard gas warhead. Syria stated that the blast was accidental and not chemical related.
Capabilities in 2013 A 2007 assessment indicated that Syria was capable of producing several hundred tons of chemical weapon agents per year.Syria Chemical Weapons at globalsecurity.org , accessed 24 October 2007. Another 2007 report said that Syria was believed to have a stockpile of hundreds of tonnes of chemical weapons agents.A Chemical Weapons–Free Middle East? csis.org, 21 May 2013Syrian Chemical Weapons observerindia.com, SEPTEMBER 2012 Syria was believed to be able to deliver chemical weapons by aerial bombs, surface-to-surface missiles and artillery rockets.
In September 2013, a French intelligence report put the Syrian stockpile at over 1,000 tonnes, including nerve agents and their precursors. This included several hundred tons of Yperite, several hundred tons of sarin, and tens of tons of VX. The report stated that Syria uses a "binary form" technique which demonstrates that Syria has acquired "great knowledge" of chemical weapon technology. As delivery systems the report highlighted as longer-range systems Scud B and Scud C missiles, with a range of 300 and 500 km respectively; and the M-600 (a Syrian version of the Iranian Fateh-110) with a range of 250–300 km. Shorter-range systems include SS21 missiles (70 km); aerial bombs; and artillery rockets and related short-range tactical systems (50 km or less). As of October 2013, some experts believe Syria has around 300 metric tonnes of sulphur mustard and around 700 metric tonnes of nerve agents. By the end of October 2013, the OPCW found a total of 1,300 metric tons of chemical weapons.
According to French intelligence, the Syrian Scientific Studies and Research Centre (SSRC) is responsible for producing toxic agents for use in war. A group named "Branch 450" is allegedly responsible for filling munitions with chemicals and maintaining security of the chemical agent stockpiles.
To provide context for these estimates, 190,000 tons of chemical weapons were manufactured by World War I combatants.
Facilities Syrian chemical weapons production facilities have been identified by Western nonproliferation experts at approximately 5 sites, plus one suspected weapons base: al-Safira (Scud missile base) Hama (Scud missile base) Homs Latakia Palmyra
Destruction
Following the Ghouta attacks, Secretary-General of the United Nations Ban Ki-moon suggested that he might request that the United Nations Security Council vote to demand that Syria ratify the CWC. On 10 September 2013, Syria announced its intention to join the chemical weapons convention, following a Russian proposal to assist Syria with disposing of their chemical arsenal, and subsequently submitted an instrument of accession to the United Nations as the depositary. Syria formally acceded to the CWC on 14 September 2013, with the convention coming into force for Syria 30 days after their deposit of the instrument of accession on 14 October 2013. In a telephone call with the Organisation for the Prohibition of Chemical Weapons (OPCW) director-general, Syrian Deputy Minister Faisal Mekdad asked for technical assistance and requested that the CWC be provisionally in force prior to its formal entry in force. The OPCW announced that this request had been circulated with its member states.
On 14 September 2013, the United States and Russia announced that they had agreed to a disarmament framework that would eliminate Syria's chemical weapons programs. Under this framework: Syria must provide a "comprehensive listing" of its weapons "within a week." Equipment for producing, mixing, and filling chemical weapons must be destroyed by November 2013. There is to be "complete elimination of all chemical weapons material and equipment in the first half of 2014."
On 27 September 2013, the OPCW agreed on an accelerated program for eliminating Syria's chemical weapons by mid-2014, consistent with this framework. On 16 October 2013, an OPCW-UN Joint Mission was established to oversee this process. The destruction of Syria's chemical weapons was completed by August 2014.
Use
Syrian civil war
At the outbreak of civil war concerns were raised about both the security of Syria's chemical weapons sites and about the potential use of chemical weapons. In July 2012, Syrian Foreign Ministry spokesman Jihad Makdissi stated that "No chemical or biological weapons will ever be used... All of these types of weapons are in storage and under security and the direct supervision of the Syrian armed forces and will never be used unless Syria is exposed to external aggression."
A Syrian defector who worked inside the chemical weapons network alleged that in January 2012 two senior Syrian officers moved about 100 kg. of chemical weapons materials from a secret military base in Nasiriyah. The Syrian source also described construction of special trucks, which could transport and mix the weapons. These mobile mixers were constructed inside Mercedes or Volvo trucks that were similar to refrigerator trucks. Inside were storage tanks, pipes and a motor to drive the mixing machinery, the defector said.